If low range detection of Fe+2 is what you need, this is the answer. Ida's Iron Check is designed to specifically react with Iron, without interference from other heavy metals that may be present. Say goodbye to dangerous, time-consuming wet-chemical kits that require extensive training and cost. This patented test is a simple dip-and-read test procedure that requires no technical training. Additionally, since there is no glass required to run the test, and since the chemical concentration is extremely low, the test is ideal for use in controlled areas. Simply dip one strip into the water for 30 seconds with a back-and-forth motion, remove the strip and shake once to remove excess water, wait 15 seconds for the color to develop, and match with the closest color match to determine your concentration of Iron.